Cobertura Reporter

A Cobertura reporter for node:test. Primarily was created in order to support GitLab's Test coverage visualization.

Also you can see the reporter in action in this GitLab repo.

Installation

npm install --save-dev cobertura

or

yarn add --dev cobertura

Usage

Define your test script:

node --test \
  --experimental-test-coverage \
  --test-reporter=cobertura --test-reporter-destination=cobertura.xml \
  --test-reporter=spec --test-reporter-destination=stdout

Your .gitlab-ci.yml can look something like this:

stages:
  - test

test:
  stage: test
  image: node:22-alpine
  artifacts:
    when: always
    reports:
      coverage_report:
        coverage_format: cobertura
        path: ./cobertura.xml
  script:
    - node -v
    - npm run test
  coverage: '/all files[^|]*\|[^|]*\s+([\d\.]+)/'

Supported Versions

The reporter can be used with node v20 and later, detailed explanation is here

Acknowledgements

This test reporter is heavily inspired by test reporters of this GitHub repo and some code parts might be directly copied from there.

Example

Source file:

export function fooOne(x) {
  if (x === 1) {
    return x + 1;
  }

  if (x === 2) {
    return x + 1;
  }

  const result = x + 1;

  return result + 1;
}

Test file:

import { describe, it } from 'node:test';
import assert from 'node:assert';
import { fooOne } from './foo.js';

describe('fooTest', () => {
  it('returns result', () => {
    const result = fooOne(12);

    assert.strictEqual(result, 14);
  });

  it('handles when x equals to 2', () => {
    const result = fooOne(2);

    assert.strictEqual(result, 3);
  });
});

Output:

<?xml version="1.0" ?>
<!DOCTYPE coverage SYSTEM "http://cobertura.sourceforge.net/xml/coverage-04.dtd">
<coverage lines-valid="30" lines-covered="28" line-rate="0.9333" branches-valid="8" branches-covered="7" branch-rate="0.8750" timestamp="1700416562185" complexity="0" version="0.1">
	<sources >
		<source >
/Users/bacebu4/dev/cobertura-test
		</source>
	</sources>
	<packages >
		<package name="cobertura-test.src" line-rate="0.9333" branch-rate="0.8750">
			<class name="foo.js" filename="src/foo.js" line-rate="0.8462" branch-rate="0.7500">
				<methods >
					<method name="fooOne" hits="2" signature="()V">
						<lines >
							<line number="1" hits="2"/>
						</lines>
					</method>
				</methods>
				<lines >
					<line number="1" hits="1" branch="true" condition-coverage="100% (2/2)"/>
					<line number="2" hits="2" branch="true" condition-coverage="0% (0/1)"/>
					<line number="3" hits="0" branch="false"/>
					<line number="4" hits="0" branch="false"/>
					<line number="5" hits="2" branch="false"/>
					<line number="6" hits="2" branch="true" condition-coverage="100% (1/1)"/>
					<line number="7" hits="1" branch="false"/>
					<line number="8" hits="1" branch="false"/>
					<line number="9" hits="1" branch="false"/>
					<line number="10" hits="1" branch="false"/>
					<line number="11" hits="1" branch="false"/>
					<line number="12" hits="1" branch="false"/>
					<line number="13" hits="2" branch="false"/>
				</lines>
			</class>
			<class name="foo.test.js" filename="src/foo.test.js" line-rate="1.0000" branch-rate="1.0000">
				<methods >
					<method name="(anonymous_0)" hits="1" signature="()V">
						<lines >
							<line number="5" hits="1"/>
						</lines>
					</method>
					<method name="(anonymous_1)" hits="1" signature="()V">
						<lines >
							<line number="6" hits="1"/>
						</lines>
					</method>
					<method name="(anonymous_2)" hits="1" signature="()V">
						<lines >
							<line number="12" hits="1"/>
						</lines>
					</method>
				</methods>
				<lines >
					<line number="1" hits="1" branch="true" condition-coverage="100% (1/1)"/>
					<line number="2" hits="1" branch="false"/>
					<line number="3" hits="1" branch="false"/>
					<line number="4" hits="1" branch="false"/>
					<line number="5" hits="1" branch="true" condition-coverage="100% (1/1)"/>
					<line number="6" hits="1" branch="true" condition-coverage="100% (1/1)"/>
					<line number="7" hits="1" branch="false"/>
					<line number="8" hits="1" branch="false"/>
					<line number="9" hits="1" branch="false"/>
					<line number="10" hits="1" branch="false"/>
					<line number="11" hits="1" branch="false"/>
					<line number="12" hits="1" branch="true" condition-coverage="100% (1/1)"/>
					<line number="13" hits="1" branch="false"/>
					<line number="14" hits="1" branch="false"/>
					<line number="15" hits="1" branch="false"/>
					<line number="16" hits="1" branch="false"/>
					<line number="17" hits="1" branch="false"/>
				</lines>
			</class>
		</package>
	</packages>
</coverage>